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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        function Star(uname, age) {
            this.uname = uname;
            this.age = age;


        }
        var that
        Star.prototype.sing = function() {
                console.log('我会唱歌');
                that = this;
            }
            /*指向 实例对象 */
        var ldh = new Star('刘德华', 15);
        ldh.sing();
        console.log(that);
    </script>
</body>

</html>